Cyclostomes are often thought as of as “primitive” because they lack jaws. In what ways could the heads of cyclostomes be considered to be derived in their own way?

Q: How does the head of Dugesia move differently from the tail?

A: Dugesia (also known as planaria) is a genus of dugesiid triclads containing the common…

Q: How many germ layers originate the body of platyhelminthes? In relation to this characteristic how…

A: Platyhelminthes, also known as flatworms, are invertebrates having bilateral symmetry. They have an…

Q: Compared to other actinopterygians, teleosts _____. reach sexual maturity later in life and live…

A: Actinopterygian refers to bony fishes which appeared during the Triassic period (50.6 million years…

Q: DEUTEROSTOMIA Chordata Chordata V [Choose ] Endostyle Anus forms at or near the site of the…

A: Blastopore :-  It is a pit in the side of the embryo, through which cells destined to be endodermal…

Q: Which of the following are shared-derived* characteristics of the species found within the Genus…

A: Shared derived characters among Genus Paranthropus.

Q: What is the tissue origin of the following: Placoid Scales Cosmoid Scales Ganoid scales Cycloid…

A: scales in fishes.

Q: Which of the following is NOT true of nemerteans? O proboscis stylet (some species) O coelomate…

A: The nemerteans are also called ribbon worms. They are characterized by the presence of proboscis and…

Q: Specifically, what are the importance of ctenophores and cnidarians to humans? Why do they need to…

A: Ctenophores are jelly-like planktonic animals that move themselves by beating rows of complex cilia…

Q: How can the features of the arthropod exoskeleton explain the terrestrial adaptation of some species…

A: The phylum Arthropoda is characterized by the presence of jointed legs, a segmented body, and an…

Q: Why are porriferans asymetrical? Cnidarians radial? The rest bilateral? (based on evolution)

A: It is required to provide the reason for assymetrical nature of poriferans, radial symmetry of…

Q: What are Trochozoans ? Explain what do they play ?

A: The Trochozoa are a proposed Lophotrochozoa clade that is sister of Polyzoa. The trochozoans clade…

Q: What is the main evolutionary innovation presented by nematodes? What is the advantage of that…

A: Nematodes are bilaterally symmetrical, elongated organisms which play a vital ecological roles as…

Q: What structural system is unique to the phylum Echinodermata?

A: Echinoderms:              Marine invertebrate animals characterized by a hard, spiny covering or…

Q: What are three organs found in Platyhelminthes that were not found in Cnidari

A: Flatworms are more advanced than cnidarians. Cnidarians are diploblastic whereas Platyhelminthes…

Q: Rotifers and acanthocephalans previously belonged to separate phylum. But recent molecular studies…

A: Rotifers are multicellular invertebrates smaller than 1 mm. They live in aquatic environments and…

Q: Differentiate artiodactyls from perissodactyls.

A: Mammals are one of the class of the  Phylum animalia.They posess certain features which…

Q: what was chracteristucs define the genus homo?

A: HOMINIDS:- Hominid are known as apes. This hominid belongs to the  Hominidae family includes a…

Q: Which of the following characteristics is not seen in the phylum Platyhelminthes?a. cephalizationb.…

A: Platyhelminthes or flatworms have the following characteristics - Acoelomate, bilateral symmetry,…

Q: Comparing to cyclostomes (primitive vertebrates) what are the main novelties presented by fishes?

A: Cyclostomes belong to the superclass Cyclostomata that comprises jawless fishes such as hagfishes…

Q: Which Platyhelminthes class lack teguments and why?

A: The classification of phylum-Platyhelminthes is based on the mode of life, i.e. Free living or…

Q: All of the following are common characters of Meandrina and Ctenoplana except a.Presence of two germ…

A: Meandrina belongs to the phylum coelenterata. Ctenoplana belongs to ctenophora.

Q: What phylum is the closest relative of nemertines? Why?

A: Nemertines:  Nemertea, sometimes known as ribbon worms or proboscis worms, is a phylum of organisms.…

Q: Label the parts that are visible of these rotifers and acanthocephalans: 1. Rotifer from class…

A: Rotifers are microscopic aquatic animals belonging to the phylum Rotifers. These are usually found…

Q: Molecular sequence data indicate that Xenoturbella is a deuteros-tome. Are there corresponding…

A: In the living world, we see a large number of microorganisms, animals and plants. These organisms…

Q: What morphological evidence suggests that nemerteans are typical coelomates?

A: Phylum Nemertea commonly called ribbon worms are bilaterally symmetrical, unsegmented organism that…

Q: Having _______ is a synapomorphy of bilaterians.

A: Having 3 germ layers is a synapomorphy of bilaterians

Q: What are three shared derived characters of deuterostomes?

A: Animal phylogeny is a rapidly changing field for biologists. Even if the members of the animal…

Q: What is the significance of having an invariant cell lineage of the nematode,

A: Caenorhabditis elegans is a model organism which help us to study various human diseases. This worm…

Q: Are all ‘choanates’ also amniotes?  Are all amniotes in the group Choanata?

A: Introduction: Any animal affiliated to the subfamily Vertebrata, the most common subphylum of the…

Q: hat features of molluscs appear in other invertebrate phyla? Explain

A: The most common properties of mollusks are covers with various vital openings used for breathing and…

Q: Examine this whole mount of Branchiostoma (amphioxus): label the notochord, myomeres, and nerve…

A: Hi, Thanks For Your Question.  Answer :  Branchiostoma do not have a true head, they only have a…

Q: Which type of tail is present in Scoliodon?

A: Fishes are gill-bearing aquatic vertebrate animals. The earliest organisms that can be first…

Q: similarities and differences among the different classes of Hemichordata and the two subphyla of…

A: All animals are categorized into different phyla in the kingdom Animalia. The animal kingdom…

Q: Compare the whole specimens and cross-sections of Ascaris and Dugesia. How would you differentiate…

A: Ascaris is an example of Nematoda and Dugesia is an example of Platyhelminths. Both are phyla of…

Q: what is the symplesiomorphic character of deuterostomes? explain

A: The study of links between various groups of species and their evolutionary development is known as…

Q: Explain why this statement is true, using phylogenetic and morphological evidence. Tunicates…

A: Tunicates are transparent or brilliantly colored marine animals that are found on the dock pilings,…

Q: Match the following groups under Phylum annelida to the following characters: Match each item to a…

A: The phylum annelida comprises worms with body walls covered with a cuticle; chitinous setae are…

Q: What are the major evolutionary features that distinguish Phylum Platyhelminthes from earlier phyla?…

A: The phylum is defined as the taxonomic rank or classification level and placed below kingdom and…

Q: What unifies the hexapoda? Be able to recognize a few of these classes by sight, and be able to…

A: Hexapods are distinguished by the decrease to six in walking annexes, with a merger of three bodies…

Q: Compare its general structures to Ascaris, Trichinella, and Enterobius. What structures are…

A: Cephalobus is a bacteriovorus soil nematode. It is a very sluggish organism. Body tapering slightly…

Q: Explain why this statement is true, using phylogenetic and morphological evidence. Tunicates…

A: Explain why this statement is true, using phylogenetic and morphological evidence.  Tunicates (…

Q: Cnidarians and ctenophores are considered diploblastic, but why might some biologists label them…

A: The process of embryonic development is characterized by the formation of the primary layers called…

Q: Phylum Echinodermata: 1. Briefly describe the general body plan of these animals by stating: a) the…

A: Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: Identify and describe the features of Rotifera and Acanthocephala that make them distinct from one…

A: Rotifera 1.  Body consists of four different regions - head, neck, trunk, foot. 2. Head has a…

Q: What is the morphological characteristic that evolutionarily approximates the beings of the phylum…

A: Annelids are defined as triploblastic, bilaterally symmetrical, metamerically segmented, acoelomate…

Q: Coelom formation in Deuterostomes is ____________ whereas in Protostomes is _____________.

A: Metazoans are classified into deuterostomes and protostomes due to their different embryonic…

Q: Examine this whole mount of Branchiostoma (amphioxus) What is the function of this notochord? What…

A: It is an example of marine invertebrate-lancelets. Falls under phylum Chordata and subphylum…

Animal Phylogeny

Cladistics is a method of biological classification where organisms are classified based on their ancestors and their relationship with them. It is defined as the concepts and methods for determining the branching patterns of evolution and evolutionary history. Some scientists, however, have preferred the term phylogenetic systematics or phylogenetic taxonomy to emphasize the reliance on a phylogeny for classification. It is the most common and accepted method for classifying organisms.